Gemology 101- How to Grade Colored Gems

June 9th, 2010 by James L. Sweaney, CGA, FGA. GG

Gemology 101 Intro

Finally, after much hard work and thought, we've launched, or rather relaunched our Mardon Colored Stone Grading System. Last year we posted most of this system along with our Gallery of Gems, but were never really satisfied with the format.

Our excellent local internet consultants, Frye/Wiles, suggested a more internet-friendly way of presenting the system to our audience. They helped us create main sections for color, clarity, cut, etc., then broke each section into its basic parts and placed these on an easy-to-use tool bar. You, the user, can quickly find the material you are interested in, and you can quickly learn a systematic approach to understanding gems and gem grading.

Our intent for the grading system was first, to provide our clients with accurate detailed gemological information about the gems we sell. As we developed the system, we realized that our method of grading also might be useful to anyone wishing to study and learn about gems.

A very important part of our mission as members of the American Gem Society and the American Gem Trade Association is consumer education. Our system gives you an inside look at how the gem industry operates. We think you will find our approach to colored gem grading useful, accessible, and built on a solid foundation of industry standards of practice.

As gem dealers, we value gems by first assessing and enjoying their beauty and sensory impact, and then grading and placing them in relative position to all the other gems we have seen. Our numerical rating system allows an accurate assessment of the position of a gem within the gem market.

As you use the system, we suggest that you tackle one section at a time, use the tool bar, and refer to the examples in our Gallery of Gems, where each gemstone has a full grading report based on this system. You'll soon see how this systematic approach provides a detailed and thorough picture of the important characteristics of a gemstone. Once you've analyzed a gem according to its components, then you should simply look and enjoy!

While the new format is aimed at presenting our system clearly and simply, we ask that you remember this is only a basic framework describing the main principals and concepts of the grading process. Actual grading skills are developed over years and years of looking at and comparing gems– this writer has been doing it for over 30 years and is still learning!

As a gem lover/consumer, please feel free to use any of our system to grade gems you own or covet. We'd love to hear your feedback, so don't hesitate to comment.